Out-of-pocket costs for prescription drugs prevent many Canadians from taking medication as directed. A new study shows 8.3 per cent – or one in 12 – Canadians ages 55 and over either skipped doses or did not fill prescription because of cost in 2014.

People who do not take medications as prescribed – known as nonadherence – are less likely to have good results from treatment, and may be at risk of having their condition progress to a more serious health problem in the future.

Researchers at the University of British Columbia’s School of Population and Public Health used data from the Commonwealth Fund’s 2014 International Health Policy Survey of Older Adults, which surveyed 5,269 Canadians ages 55 and over by phone. The UBC researchers found that age, income, health status and access to private health insurance all influenced whether people skipped medication doses or did not fill prescriptions because of costs:

People ages 55 to 64 were three times as likely as those 65 and over to not use prescriptions as directed because of costs. It’s likely that this is because many provinces have public drug coverage for people ages 65 and over.

Not surprisingly, people with low incomes were more than three times as likely as those with average incomes to not take their medication as directed for financial reasons. However, this difference was only seen in the 55 to 64 age group, and not in the 65 and over age group. Again, this probably reflects the availability of public drug coverage for those over 65.

People who rated their health as fair or poor were 75 per cent more likely than those who said their health was good or excellent to skip doses or prescriptions because of cost.

Those who did not have private health insurance were twice as likely to not take their medication as prescribed, compared to those with private coverage.

The results show that even with universal access to healthcare, there are financial barriers to treatment if people are unable to take their medication because of costs. The study authors call the financial inaccessibility of prescription medicines in Canada a substantial public health issue, and note that it affects one in 12 people in this age group.

The study, which was led by Steve Morgan, PhD, was published in CMAJ Open on Jan. 18, 2017.